Navigation

The rbd command enables you to create, list, introspect and remove block
device images. You can also use it to clone images, create snapshots,
rollback an image to a snapshot, view a snapshot, etc. For details on using
the rbd command, see RBD – Manage RADOS Block Device (RBD) Images for
details.

Important

To use Ceph Block Device commands, you must have access to
a running Ceph cluster.

Unless specified, the rbd command will access the Ceph cluster using the ID
admin. This ID allows full administrative access to the cluster. It is
recommended that you utilize a more restricted user wherever possible.

Ceph Block Device images are thin provisioned. They don’t actually use
any physical storage until you begin saving data to them. However, they do have
a maximum capacity that you set with the --size option. If you want to
increase (or decrease) the maximum size of a Ceph Block Device image, execute
the following: